llvm/lib/Support/Debug.cpp
2009-07-20 16:16:06 +00:00

86 lines
3.1 KiB
C++

//===-- Debug.cpp - An easy way to add debug output to your code ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements a handle way of adding debugging information to your
// code, without it being enabled all of the time, and without having to add
// command line options to enable it.
//
// In particular, just wrap your code with the DEBUG() macro, and it will be
// enabled automatically if you specify '-debug' on the command-line.
// Alternatively, you can also use the SET_DEBUG_TYPE("foo") macro to specify
// that your debug code belongs to class "foo". Then, on the command line, you
// can specify '-debug-only=foo' to enable JUST the debug information for the
// foo class.
//
// When compiling in release mode, the -debug-* options and all code in DEBUG()
// statements disappears, so it does not effect the runtime of the code.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
bool llvm::DebugFlag; // DebugFlag - Exported boolean set by the -debug option
namespace {
#ifndef NDEBUG
// -debug - Command line option to enable the DEBUG statements in the passes.
// This flag may only be enabled in debug builds.
static cl::opt<bool, true>
Debug("debug", cl::desc("Enable debug output"), cl::Hidden,
cl::location(DebugFlag));
static std::string CurrentDebugType;
static struct DebugOnlyOpt {
void operator=(const std::string &Val) const {
DebugFlag |= !Val.empty();
CurrentDebugType = Val;
}
} DebugOnlyOptLoc;
static cl::opt<DebugOnlyOpt, true, cl::parser<std::string> >
DebugOnly("debug-only", cl::desc("Enable a specific type of debug output"),
cl::Hidden, cl::value_desc("debug string"),
cl::location(DebugOnlyOptLoc), cl::ValueRequired);
#endif
}
// isCurrentDebugType - Return true if the specified string is the debug type
// specified on the command line, or if none was specified on the command line
// with the -debug-only=X option.
//
bool llvm::isCurrentDebugType(const char *DebugType) {
#ifndef NDEBUG
return CurrentDebugType.empty() || DebugType == CurrentDebugType;
#else
return false;
#endif
}
/// getNullOutputStream - Return a null string that does not output
/// anything. This hides the static variable from other modules.
///
OStream &llvm::getNullOutputStream() {
static llvm::OStream NullStream(0);
return NullStream;
}
// getErrorOutputStream - Returns the error output stream (std::cerr). This
// places the std::c* I/O streams into one .cpp file and relieves the whole
// program from having to have hundreds of static c'tor/d'tors for them.
//
OStream &llvm::getErrorOutputStream(const char *DebugType) {
static OStream cnoout(0);
if (DebugFlag && isCurrentDebugType(DebugType))
return cerr;
else
return cnoout;
}